fgetpos(3S)fgetpos(3S)NAME
fgetpos(), fsetpos() - save and restore a file position indicator for a stream
SYNOPSIS DESCRIPTION
Store the current value of the file position indicator
for the stream pointed to by stream in the object pointed to by pos. The value stored contains information usable by for
repositioning the stream to its position at the time of the call to
Set the file position indicator for the stream pointed to by
stream according to the value of the object pointed to by pos, which must be a value set by an earlier call to on the same
stream.
A successful call to clears the end-of-file indicator for the stream and undoes any effects of ungetc(3S) on the same
stream. After a call, the next operation on a update stream can be either input or output.
RETURN VALUE
If successful, these functions return zero; otherwise non-zero.
ERRORS
If fails, is set to one of the following values.
[EINVAL] The current value of the file position cannot be represented correctly in an object of size in this environment.
Additional values may be set by the underlying function (see fseek(3S)).
WARNINGS
Failure can occur if these functions are used on a file that has not been opened via In particular, they must not be used on a terminal or
on a file opened via popen(3S).
has no effect on streams that are open for append (see fopen(3S)).
SEE ALSO fgetpos64(3S), fseek(3S), fopen(3S), popen(3S), ungetc(3S), thread_safety(5), glossary(9).
STANDARDS CONFORMANCE fgetpos(3S)
Check Out this Related Man Page
FSEEK(3) Linux Programmer's Manual FSEEK(3)NAME
fgetpos, fseek, fsetpos, ftell, rewind - reposition a stream
SYNOPSIS
#include <stdio.h>
int fseek(FILE *stream, long offset, int whence);
long ftell(FILE *stream);
void rewind(FILE *stream);
int fgetpos(FILE *stream, fpos_t *pos);
int fsetpos(FILE *stream, fpos_t *pos);
DESCRIPTION
The fseek function sets the file position indicator for the stream pointed to by stream. The new position, measured in bytes, is obtained
by adding offset bytes to the position specified by whence. If whence is set to SEEK_SET, SEEK_CUR, or SEEK_END, the offset is relative to
the start of the file, the current position indicator, or end-of-file, respectively. A successful call to the fseek function clears the
end-of-file indicator for the stream and undoes any effects of the ungetc(3) function on the same stream.
The ftell function obtains the current value of the file position indicator for the stream pointed to by stream.
The rewind function sets the file position indicator for the stream pointed to by stream to the beginning of the file. It is equivalent
to:
(void)fseek(stream, 0L, SEEK_SET)
except that the error indicator for the stream is also cleared (see clearerr(3)).
The fgetpos and fsetpos functions are alternate interfaces equivalent to ftell and fseek (with whence set to SEEK_SET), setting and storing
the current value of the file offset into or from the object referenced by pos. On some non-UNIX systems an fpos_t object may be a complex
object and these routines may be the only way to portably reposition a text stream.
RETURN VALUE
The rewind function returns no value. Upon successful completion, fgetpos, fseek, fsetpos return 0, and ftell returns the current offset.
Otherwise, -1 is returned and the global variable errno is set to indicate the error.
ERRORS
EBADF The stream specified is not a seekable stream.
EINVAL The whence argument to fseek was not SEEK_SET, SEEK_END, or SEEK_CUR.
The function fgetpos, fseek, fsetpos, and ftell may also fail and set errno for any of the errors specified for the routines fflush(3),
fstat(2), lseek(2), and malloc(3).
CONFORMING TO
The fgetpos, fsetpos, fseek, ftell, and rewind functions conform to ANSI X3.159-1989 (``ANSI C'').
SEE ALSO lseek(2), fseeko(3)BSD MANPAGE 1993-11-29 FSEEK(3)